Angular -custom directive for dynamic direction (rtl or ltr)

angular-custom-directive.ts

@Directive({
  selector: '[setDirection]'
})
export class SetDirDirective {
  /**
   * 
   * @param el 
   * @param languageService 
   * @param locale 
   */
  constructor(private element: ElementRef,
    private languageService: LanguageService,
  ) {
    this.onChangeLanguage();
  }

  onChangeLanguage() {
    this.languageService.language.subscribe((languageCode:string) => {
      switch (languageCode) {
        case 'ar':
          this.element.nativeElement.style.direction = 'rtl';
          this.element.nativeElement.style.textAlign = 'right';
          break;

        default:
          this.element.nativeElement.style.direction = 'ltr';
          this.element.nativeElement.style.textAlign = 'left';
          break;
      }
    });
  }
}